Previously, we have shown the inhibitory effect of chloroquine on the infectivity of human immunodeficiency virus (HIV-1) in human T-cell lines. The data suggests that chloroquine inhibition of infectious virus production is most likely due to interference with terminal sialylation in the trans-Golgi network. We will test this drug alone or in combination with other drugs on primary cell cultures. Experiments are in progress to establish a primary peripheral blood lymphocyte/monocyte culture system for this purpose and to develop quantitative bioassays for detection of primary cultures that are infected with HIVs. In addition, attempts have been made to identify potential anti-HIV agents from traditional Chinese herbs. A new inhibitor of HIV infection and replication has been isolated and purified to homogeneity from the seeds and fruits of the Chinese medicinal plant Momaordica Charantia. This protein, MAP 21, has been sequenced and sequence comparison revealed homology with the ricin A chain and with several forms of trichosanthins. No cytotoxicity was found under the culture conditions for anti-HIV assay. Therefore, MAP 21 could be a potential anti-AIDS drug. Besides MAP 21, we have identified two other Chinese herbs with anti-HIV activity, i.e. Baicalin and Phyllanthus.